I thought I had done this before, but maybe not. My time this evening with composite and participating address locators and ArcGIS Server 10.2 have left me with a few questions:

1) When publishing a composite locator from a file geodatabase as a geocode service, must the participating locators reside in the same file geodatabase as the composite? I ran into a scenario tonight where the extant locators participating in my composite were not copied to the server upon publishing, even though they resided in another file geodatabase in the same directory structure (and yes, the ArcGIS Server account has the appropriate permissions on all levels of that directory structure).

2) If participating locators can be located in separate file geodatabases from the composite, can they be named the same as other participating locators from other geodatabases? I noticed when the locators are copied that only the actual file name is listed, and perhaps this was my issue to begin with. The locators I used tonight referenced similar feature classes with common naming conventions and were named after them, so there were duplicate address locator names that were differentiated in the composite with an alias "_A" and "_B" (and, of course, by the Location).

In order to get my composite to correctly publish tonight, I had to re-create all extant locators in the same file geodatabase as my composite, obviously with unique names. Kindof a hassle when the individual locators are not just there to feed the composite and therefore it makes better sense to have them reside with the data they reference and/or not have duplicate locators based on usage.

To begin with, I suggest that you build and keep your locators in a directory rather than a geodatabse. I started doing this a few years ago at the suggestion of an ESRI post here on the forum. It allows you to maintain your locators as such, rather than a database object and hence all the over head of a geodatabase is eliminated with resepct to the locator. From the directory you can point to whatever (and where ever) feature class you want. Just be sure to use relative paths; it makes life easier.

Naming locators is up to you. I use a series of locators that are combined into a composite that I publish and use in 9-1-1 dispatch. However, I have two locator directories: SystemA and SystemB. Both directories have have the same named locators that point back to the same feature classes in the the same geodatabase. At any given time, if SytemA is 'hot', SystemB is not. By hot, I mean being utilized for dispatch. In this configuration, I can make updates to the feature classes that the various locators point to, and rebuild the locators in the 'cold' system; the published locator must be stopped in order to do this. Once all locators are rebuilt, simply start the published locator and the updated data is being accessed. Essentially, I toggle dispatch back and forth between Hot and Not for updates.

I'm not sure what you mean by all extant locators. Perhaps you could elaborate.